| Complement-fixation. No positive reaction between Lassa antigen in dilution 1:4 (homologous titer = 16) and the following polyvalent or individual immune ascitic fluids (homologous titers in parentheses): Group A (32-256), Group B (16-256), Group C (64-128), Congo (256), EHD-NJ (16), Marburg (64), Nairobi sheep disease (128), Piry (64), Rift Valley fever (256), simian hemorrhagic fever (256). No positive reaction between human convalescent sera, patient LP (homologous titer = 64 and 128) at dilution 1:8 and higher and the following antigens at dilutions 1:4 and 1:8: Acara, Akabane, Amapari, Anopheles A, Anopheles B, Aruac, Bahig, Agua Preta. Benfica, Belem, Bertioga, Bhanja, Boracea, Bunyamwera, Bushbush, Navarro, California, Capim, Chaco, Chandipura, Changuinola, Buenaventura, CoAr 3627, Cocal, CTF, Congo, Cotia, Matariya, EgAn 1825-61, Burg el Arab, Embu, EMC, EHD-NJ, EthAr 1846-64, Farallon, Flanders, Guajara, Guama, Guaroa, Germiston, Hart Park, mouse hepatoencephalitis, herpes, Hughes, Oyo, Gabek Forest (IbAn 10065), Arumowot (IbAn 15736), IbAn 17143, Jos, IbAn 20433, Orungo (IbH 11306), Ieri, Nyando, Irituia, J-19, J-134, Johnston Atoll, Junin, Jurona, Kamese, Kemerovo, Kern Canyon, Ketapang, Koongol Kwatta, LCM, Lagos bat, Lone Star, Lukuni, Machupo, Marburg, Marco, Klamath, Mirim, Mossuril, Mt. Elgon bat, NDV, Nyamaninni, Nyando, Omsk hem. fever, Oropouche, Piry, Naples SF, Sicilian SF, polioencephalitis of mice, poxvirus, Pacui, Pichinde, Punta Toro, rabies, Lebombo, Sathuperi, Sawgrass, Silverwater, simian hemorrhagic fever, Soldado, SudAr 1169-64, SudAr 1275-64, SudAr 1225-64, Tacaribe, Tacaiuma, Tamiami, Tataguine, Tembe, Thogoto, Triniti, Turlock VSI, VSNJ, Wad Medani, Witwatersrand, yellow fever and Nkolbisson. | Using mouse hyperimmune sera and ascitic fluids against Lassa and LCM viruses, a low titered but reproducible cross-reaction is detected between these two viruses, also with some of the antigens of the established Tacaribe group, as shown below ( [1] , and unpublished). | | | Mouse Hyperimmune Immune Serum or Ascitic Fluid |
---|
Antigen | Lassa 1 | Lassa 2 | LCM 1 | LCM 2 | Amapari | Tacaribe | Pichinde |
---|
|
| Reciprocal of dilution; 0 = no fixation, dilution 1:2 | Lassa | 256 | 256 | 4 | 2 | 0 | 0 | 0 | LCM | 16 | 16 | 256 | 256 | 4 | 2 | 4 | Tacarib | 4 | 4 | | | | 512 | | Amapari | 4 | 16 | | | 256 | | | Junin | 4 | 2 | | | | | | Tamiami | 0 | 2 | | | | | | Pichind | 0 | 0 | | | | | 512 | Controls | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Serological differences have been noted between Lassa virus and a "Lassa- like" isolate obtained in Mozambique [17] . In addition, a monoclonal antibody prepared against LCM virus reacted in an immunofluorescence test with the Mozambique isolate, but not with Lassa virus [20] . | |
|